Cataracts are layers over a person's eyes that prevent them from seeing properly. Cataracts usually develop because of old age or illness.
例句
In one study, light smokers were found to be more than twice as likely to get cataracts as non-smokers...研究表明，即使抽烟不多的人也比不抽烟的人患白内障的概率高出一倍多。Age is not a factor in cataract surgery.年龄并不是影响做白内障手术的因素。
N-COUNT
大瀑布
A cataract is a large waterfall.
英汉词典释义
n.
大瀑布
The way is blocked by the tall cataract.高悬的大瀑布挡住了去路。
<医>白内障
He is an elderly gentleman who had had a cataract operation.他是一位曾经动过白内障手术的老人。
英英词典释义
Noun
1. clouding of the natural lens of the eye
2. a large waterfall; violent rush of water over a precipice